The dynamics of diplomacy in Northeast Asia are fast evolving in relation to the North Korean nuclear problem. The past week alone witnessed a flurry of visits and meetings focused on denuclearization.

US Secretary of State Mike Pompeo led the hectic diplomatic schedules, making a swing of the region. He met Japanese Prime Minister Shinzo Abe before making his fourth trip to North Korea to reinvigorate the denuclearization process. Then he had a debriefing session with President Moon Jae-in in Seoul before flying to Beijing to meet Chinese officials.

Pompeo’s series of visits centered on reviving the denuclearization process that had been stalled since the historic meeting between US President Donald Trump and North Korean leader Kim Jong-un in June. After his visit to Pyongyang, Pompeo said the second Trump-Kim meeting would be held “at the earliest possible date.” That was a good sign.

Though less conspicuous than Pompeo, there was another diplomat -- one from North Korea – in action over the past few days. The activities of North Korean Vice Foreign Minister Choe Sun-hui deserve attention.

Instead of receiving Pompeo’s entourage, which included her US counterpart Stephen Biegun, the special representative for the North, Choe went to Beijing to meet Chinese Vice Foreign Minister Kong Xuanyou.

The North Korean diplomat then flew to Moscow, where she met her Russian counterpart Igor Morgulov on Monday. Choe’s diplomatic schedules were highlighted by a three-way meeting with Kong and Morgulov in Moscow on Tuesday.

Such a trilateral meeting of senior diplomats from the three neighboring countries is quite rare, and its timing commands close attention from those involved in the North Korean denuclearization process.

Most of all, it is apparent that the three countries are trying to form a sort of alliance at a time when North Korea is bracing for crucial denuclearization talks with the US, which has been working closely with South Korea and Japan.

In short, there are signs of a “northern alliance” in the making vis-a-vis the three-way alliance involving Seoul, Washington and Tokyo. Senior Russian officials already said they were working for Kim’s visit to Moscow, the first since the North Korean leader took power in 2011.

Chinese President Xi Jinping is also expected to pay a visit to Pyongyang soon, which will reciprocate Kim’s three visits to Beijing this year. Now some even raise the possibility of Kim, Putin and Xi holding a tripartite summit similar to that of the South Korean, US and Japanese leaders.

Indeed, each of the three countries have something to gain by forging a joint front. North Korea can get support from its two ideological allies and economic benefactors both of whom are permanent members of the UN Security Council. China and Russia have already been pressuring the Council to ease the sanctions imposed on the North.

For their part, China and Russia could use their influence on North Korea as a card in dealing with the US. That could act as a negative factor in the US handling of the denuclearization issue.

The fast consolidation of ties among the three countries calls on the other key players -- namely South Korea, the US and Japan -- to exercise wisdom -- to keep them in check on one hand and entice cooperation from them on the other.

The problem is that the alliance between Seoul, Washington and Tokyo is hardly seamless as far as how to deal with North Korea. For instance, Japan holds the most hardline stance against the North, insisting that sanctions remain in place and the US declaration of the end of the Korean War with North Korea should not precede substantial progress in denuclearization.

In contrast, the South Korean government led by President Moon is prodding the US to take what the North says are “corresponding measures” to some denuclearization steps taken by the North. The Moon government is also inclined to lift some of the sanctions against the North to promote reconciliation and peace projects with the North.

What the diplomats from the three northern countries have been doing over the past few days, which will certainly be followed by interactions of their leaders, should be a reminder that the South Korea-US-Japan alliance should not be swayed until a complete denuclearization of the North is achieved.